/**
 * 
 */
package com.platform.common.utils;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;

/**
 * <pre>
 * 功能：反射工具类 提供调用getter/setter方法, 访问私有变量, 调用私有方法, 获取泛型类型Class, 被AOP过的真实类等工具函数
 * </pre>
 * 
 * @author wei.gao
 */
public final class ReflectionUtils extends org.springframework.util.ReflectionUtils {
	
	private static final String SETTER_PREFIX = "set";
	
	private static final String GETTER_PREFIX = "get";
	
	private static final String CGLIB_CLASS_SEPARATOR = "$$";
	
	/**
	 * <pre>
	 * 功能：调用Getter方法.
	 * </pre>
	 * 
	 * @param obj
	 * @param propertyName
	 * @return
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 * @throws InvocationTargetException
	 */
	public static Object invokeGetter(Object obj, String propertyName) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(propertyName);
		return invokeMethod(obj, getterMethodName, new Class[] {}, new Object[] {});
	}
	
	/**
	 * <pre>
	 * 功能：调用Setter方法, 仅匹配方法名。
	 * </pre>
	 * 
	 * @param obj
	 * @param propertyName
	 * @param value
	 * @throws InvocationTargetException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static void invokeSetter(Object obj, String propertyName, Object value) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		String setterMethodName = SETTER_PREFIX + StringUtils.capitalize(propertyName);
		invokeMethodByName(obj, setterMethodName, new Object[] { value });
	}
	
	/**
	 * <pre>
	 * 功能：直接读取对象属性值, 无视private/protected修饰符, 不经过getter函数.
	 * </pre>
	 * 
	 * @param obj
	 * @param fieldName
	 * @return
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 */
	public static Object getFieldValue(final Object obj, final String fieldName) throws IllegalArgumentException, IllegalAccessException {
		Field field = getAccessibleField(obj, fieldName);
		
		if (field == null) {
			throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
		}
		
		Object result = field.get(obj);
		return result;
	}
	
	/**
	 * <pre>
	 * 功能：直接设置对象属性值, 无视private/protected修饰符, 不经过setter函数.
	 * </pre>
	 * 
	 * @param obj
	 * @param fieldName
	 * @param value
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static void setFieldValue(final Object obj, final String fieldName, final Object value) throws IllegalArgumentException, IllegalAccessException {
		Field field = getAccessibleField(obj, fieldName);
		
		if (field == null) {
			throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
		}
		
		field.set(obj, value);
	}
	
	/**
	 * <pre>
	 * 功能：直接调用对象方法, 无视private/protected修饰符.
	 * 用于一次性调用的情况，否则应使用getAccessibleMethod()函数获得Method后反复调用. 同时匹配方法名+参数类型，
	 * </pre>
	 * 
	 * @param obj
	 * @param methodName
	 * @param parameterTypes
	 * @param args
	 * @return
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 * @throws InvocationTargetException
	 */
	public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes, final Object[] args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		Method method = getAccessibleMethod(obj, methodName, parameterTypes);
		if (method == null) {
			throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
		}
		
		return method.invoke(obj, args);
	}
	
	/**
	 * <pre>
	 * 功能：直接调用对象方法, 无视private/protected修饰符，
	 * 用于一次性调用的情况，否则应使用getAccessibleMethodByName()函数获得Method后反复调用.
	 * 只匹配函数名，如果有多个同名函数调用第一个。
	 * </pre>
	 * 
	 * @param obj
	 * @param methodName
	 * @param args
	 * @return
	 * @throws InvocationTargetException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static Object invokeMethodByName(final Object obj, final String methodName, final Object[] args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		Method method = getAccessibleMethodByName(obj, methodName);
		if (method == null) {
			throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
		}
		
		return method.invoke(obj, args);
	}
	
	/**
	 * <pre>
	 * 功能：循环向上转型, 获取对象的DeclaredField, 并强制设置为可访问. 如向上转型到Object仍无法找到, 返回null.
	 * </pre>
	 * 
	 * @param obj
	 * @param fieldName
	 * @return
	 */
	public static Field getAccessibleField(final Object obj, final String fieldName) {
		Validate.notNull(obj, "object can't be null");
		Validate.notBlank(fieldName, "fieldName can't be blank");
		for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
			try {
				Field field = superClass.getDeclaredField(fieldName);
				makeAccessible(field);
				return field;
			} catch (NoSuchFieldException e) {//NOSONAR
				// Field不在当前类定义,继续向上转型
			}
		}
		return null;
	}
	
	/**
	 * <pre>
	 * 功能：循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问. 如向上转型到Object仍无法找到, 返回null.
	 * 匹配函数名+参数类型。 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
	 * </pre>
	 * 
	 * @param obj
	 * @param methodName
	 * @param parameterTypes
	 * @return
	 */
	public static Method getAccessibleMethod(final Object obj, final String methodName, final Class<?>... parameterTypes) {
		for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
			try {
				Method method = searchType.getDeclaredMethod(methodName, parameterTypes);
				makeAccessible(method);
				return method;
			} catch (NoSuchMethodException e) {
				// Method不在当前类定义,继续向上转型
			}
		}
		return null;
	}
	
	/**
	 * <pre>
	 * 功能：循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问. 如向上转型到Object仍无法找到, 返回null. 只匹配函数名。
	 * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
	 * </pre>
	 * 
	 * @param obj
	 * @param methodName
	 * @return
	 */
	public static Method getAccessibleMethodByName(final Object obj, final String methodName) {
		for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
			Method[] methods = searchType.getDeclaredMethods();
			for (Method method : methods) {
				if (method.getName().equals(methodName)) {
					makeAccessible(method);
					return method;
				}
			}
		}
		return null;
	}
	
	/**
	 * <pre>
	 * 功能：改变private/protected的方法为public，尽量不调用实际改动的语句，避免JDK的SecurityManager抱怨。
	 * </pre>
	 * 
	 * @param method
	 */
	public static void makeAccessible(Method method) {
		if ((!Modifier.isPublic(method.getModifiers()) || !Modifier.isPublic(method.getDeclaringClass().getModifiers())) && !method.isAccessible()) {
			method.setAccessible(true);
		}
	}
	
	/**
	 * <pre>
	 * 功能：改变private/protected的成员变量为public，尽量不调用实际改动的语句，避免JDK的SecurityManager抱怨。
	 * </pre>
	 * 
	 * @param field
	 */
	public static void makeAccessible(Field field) {
		if ((!Modifier.isPublic(field.getModifiers()) || !Modifier.isPublic(field.getDeclaringClass().getModifiers()) || Modifier.isFinal(field.getModifiers())) && !field.isAccessible()) {
			field.setAccessible(true);
		}
	}
	
	/**
	 * <pre>
	 * 功能：通过反射, 获得Class定义中声明的泛型参数的类型, 注意泛型必须定义在父类处
	 * 如无法找到, 返回Object.class.
	 * eg.
	 * public UserDao extends HibernateDao<User>
	 * </pre>
	 * 
	 * @param clazz
	 * @return
	 */
	public static Class<?> getClassGenricType(final Class<?> clazz) {
		return getClassGenricType(clazz, 0);
	}
	
	/**
	 * <pre>
	 * 功能：通过反射, 获得Class定义中声明的父类的泛型参数的类型.
	 * 如无法找到, 返回Object.class.
	 * 
	 * 如public UserDao extends HibernateDao<User,Long>
	 * </pre>
	 * 
	 * @param clazz
	 * @param index
	 * @return
	 */
	public static Class<?> getClassGenricType(final Class<?> clazz, final int index) {
		Type genType = clazz.getGenericSuperclass();
		
		if (!(genType instanceof ParameterizedType)) {
			return Object.class;
		}
		
		Type[] params = ((ParameterizedType) genType).getActualTypeArguments();
		
		if (index >= params.length || index < 0) {
			return Object.class;
		}
		if (!(params[index] instanceof Class)) {
			return Object.class;
		}
		
		return (Class<?>) params[index];
	}
	
	/**
	 * <pre>
	 * 功能：
	 * </pre>
	 * 
	 * @param instance
	 * @return
	 */
	public static Class<?> getUserClass(Object instance) {
		Class<?> clazz = instance.getClass();
		if (clazz != null && clazz.getName().contains(CGLIB_CLASS_SEPARATOR)) {
			Class<?> superClass = clazz.getSuperclass();
			if (superClass != null && !Object.class.equals(superClass)) {
				return superClass;
			}
		}
		return clazz;
	}
	
	/**
	 * <pre>
	 * 功能：获得调用的方法名
	 * </pre>
	 * 
	 * @return
	 */
	public static String getInvokeMethodName() {
		String methodName = null;
		Thread thr = Thread.currentThread();
		StackTraceElement[] ele = thr.getStackTrace();
		methodName = ele[ele.length > 3 ? 3 : 2].getMethodName();
		return methodName;
	}
	
	/**
	 * <pre>
	 * 功能：获得调用的类
	 * </pre>
	 * 
	 * @return
	 * @throws ClassNotFoundException
	 */
	public static Class<?> getInvokeClass() throws ClassNotFoundException {
		Class<?> clazz = null;
		Thread thr = Thread.currentThread();
		StackTraceElement[] ele = thr.getStackTrace();
		clazz = Class.forName(ele[ele.length > 3 ? 3 : 2].getClassName());
		return clazz;
	}
	
	/**
	 * <pre>
	 * 功能：获得调用的类名
	 * </pre>
	 * 
	 * @return
	 */
	public static String getInvokeClassName() {
		String clazzName = null;
		Thread thr = Thread.currentThread();
		StackTraceElement[] ele = thr.getStackTrace();
		clazzName = ele[ele.length > 3 ? 3 : 2].getClassName();
		return clazzName;
	}
}
